﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp18
{
    class calculation
    {
        public double A(double r) 
        {
            double sum = 3.14 * r * r;
            Console.WriteLine("和"+sum);
            return sum;
        }
        public int B(int c,int k) 
        {
            int sum = c * k;
            Console.WriteLine("和" + sum);
            return sum;
        }
    }
    
}
